X-Git-Url: https://git.distorted.org.uk/~mdw/catacomb/blobdiff_plain/0f00dc4c8eb47e67bc0f148c2dd109f73a451e0a..141c12847a1c2f8cc8db03d420551584e689fb87:/progs/factorial.c

diff --git a/progs/factorial.c b/progs/factorial.c
index a46debd1..ece0b305 100644
--- a/progs/factorial.c
+++ b/progs/factorial.c
@@ -34,6 +34,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 
+#include <mLib/macros.h>
 #include <mLib/mdwopt.h>
 #include <mLib/quis.h>
 #include <mLib/report.h>
@@ -130,12 +131,12 @@ int main(int argc, char *argv[])
   }
   ulmax = mp_fromulong(MP_NEW, ULONG_MAX);
   p = argv[optind];
-  while (isspace((unsigned char)*p))
+  while (ISSPACE(*p))
     p++;
   xx = mp_readstring(MP_NEW, argv[optind], &p, 0);
-  while (isspace((unsigned char)*p))
+  while (ISSPACE(*p))
     p++;
-  if (!xx || *p || MP_CMP(xx, >, ulmax))
+  if (!xx || *p || MP_CMP(xx, <, MP_ZERO) || MP_CMP(xx, >, ulmax))
     die(EXIT_FAILURE, "bad integer `%s'", argv[optind]);
   x = mp_toulong(xx);
   mp_drop(xx);